1. Field of the Invention
The present disclosure relates to systems for generating electrical power, and more particularly to high-speed generators having open loop actively cooled rotors.
2. Description of Related Art
Conventional space vehicles use on-board generators to provide power for various on-board devices. Developments towards the “more-electric” space vehicle have led to increased power demands to support on-board electrical equipment employed in such space vehicle architectures. High-speed generators, e.g. generators having rotational components with speeds approaching or exceeding 250,000 rotations per minute, are of interest in meeting these needs due to their relative compactness, efficiency, and high energy density.
One challenge with high-speed generators is that windage effects in the gap between the rotor and stator makes removing heat generated from magnetic eddy losses and resistive heating difficult. This is because, at high rotational speeds, the frictional viscous drag of the fluid against the rotor surface heats the fluid sufficiently to make heat transfer less readily across the gap from the rotor to the stator. It also can make maintaining the gap clearance difficult. Conventional terrestrial generators, such as utility generators, employ closed loop rotor and stator cooling systems for removing heat, often using relatively massive and complex cryogenic systems.
Conventional systems and methods for space vehicle power generation have generally been considered satisfactory for their intended purpose. However, there is a need for improved generators that are efficient and have high power density. There also remains a need for generators that are easy to make and use. The present disclosure provides solutions for these needs.